Determination of Required Falling Weight Deflectometer Testing Frequency for Pavement Structural Evaluation at the Network Level

Abstract

Recently, a structural condition index (SCI) was developed for the Texas Department of Transportation as a screening tool to discriminate between pavements that need structural reinforcement from those that do not. For the successful implementation of the SCI concept at the network level, one of the critical issues is to determine the minimum falling weight deflectometer (FWD) testing frequency. The paper discusses how to determine the required FWD testing frequency, or the required FWD test spacing needed for implementing the SCI at the network level. In this study, the risk-based method was employed, where the variance of the SCI at the network level was assessed by randomly selecting a small sample of the pavement sections that were representative of the whole network. Due to the limited number of such sections and the lack of knowledge of underlying distribution of the SCI variances at the network level, the bootstrap method was used to obtain the mean and the confidence intervals on the mean of the SCI variances at the network level.